Serological and molecular detection of Leptospira spp. from small wild mammals captured in Sarawak, Malaysia

Aims: Leptospirosis is endemic to tropical regions of the world and is re-emerging as a new danger to public health in Southeast Asia, including Malaysia. The purpose of this particular study was to determine the common leptospiral serovars present in small wild mammals living around wildlife reserves and disturbed forest habitats and human communities. Methodology and results: The samples of blood and kidneys of small rodents, bats and squirrels were analyzed. Antibodies to different serovars of leptospires were detected in 73 of 155 wild small mammals captured (47.0%: 95% CI 39.0-55.3%). The seroprevalence for rats (57.9%; 95% CI 44.1-70.9) was slightly higher than that for squirrels (42.9%; 95% CI 24.5-62.8) and bats (40%; 95% CI 28.5-52.4). Seropositive animals were detected in all 5 localities sampled. Antibodies to serovar Lepto 175 Sarawak were detected in 30 (24.7%) rats, 11 (9.0%) squirrels and 27 (52.9%) bats. Of 155 kidney samples from individual animals only 17 were positive for Leptospira on a molecular study (10.97%, 95% CI 6.5-17). The majority of the positive results were from plantain squirrels (53%; 95% CI 27.8, 77), Muller's rat (35%; 95% CI 14.2, 61.7) and brown spiny rats (12%; 95% CI 1.5, 36.4). Conclusion, significance and impact of study: This particular study should generate concerns and lead to the health authorities expanding disease control measures in the region as there are significant levels of human activity at all five locations where the animals were sampled. The pathogenesis of serovar Lepto 175 Sarawak also needs to be monitored closely, considering its similarities to the pathogenic Leptospira wolffii.